ABSTRACT: Five batches from
the same stock of seeds of Ocimum
basilicum were irradiated at 5, 10, 15, 20 and 25 Gy, respectively using 60C
source. Methanolic leaf extracts of these samples and a control were evaluated
for their antioxidant activity by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH)
free radical scavenging method using M2 plants. All the methanolic
extracts showed antioxidant activity. The IC50 of the methanolic
extracts of the six different treatments, control, 5 Gy, 10 Gy, 15 Gy, 20 Gy
and 25 Gy, showed antioxidant activity with IC50 values of 100, 90,
86, 61, 71 and 70 μg/ml, respectively. Three individual mutants, M-15-5, M-20-6
and M-15-4, had IC50 values of 26, 30 and 40 μg/ml, respectively.
These mutants were from the 15 Gy and 20 Gy treatments. From the results, it is
confirmed that induced mutation can be employed to create variation in the
levels of free radical scavenging activity in O. basilicum and can therefore serve as a tool for breeding for
high levels of antioxidant activity in O.
basilicum.